Frequently Asked Questions (FAQ) about Integrated Water Management Services

How does IWM fit with the LEED™ green building program?

IWM fits very well with both Sustainable Sites (SS) and Water Efficiency (WE) credits. In the LEED™ New Construction and Major Renovation system, SS Credit 6 for Stormwater Management offers one point for preventing the discharge of excessive amounts of stormwater and one point for treating stormwater before it is released. IWM practices would achieve both of these credits. Also, WE Credit 1 for Water Efficient Landscaping could provide one or two points for limiting or eliminating potable water use for landscape irrigation and one point for reducing wastewater generation or for treating the wastewater and returning it to the local watershed. Other WE points apply to decreasing potable water use within buildings.

Is captured stormwater safe to use?

Rainwater that is collected from building roofs should be fairly clean, and might be used, after appropriate treatment, to supplement potable water supplies. The quality of stormwater collected from ground surfaces will vary significantly across a site. The best uses of this water would be those that do not involve human consumption. This water would likely be very suitable for landscape irrigation, as long as precautions are taken to avoid accidental ingestion.

What degree of treatment is required for wastewater reuse?

Some states have explicit treatment requirements, while others would take a case-by-case approach. The American Water Works Association, in its Manual of Water Supply Practices for Dual Water Systems (AWWA M24), recommends a range of treatment requirements, depending on the proposed use and the likelihood of human exposure. The least degree of treatment, secondary with disinfection - the prevailing treatment requirement for discharge to most surface waters - would apply to uses that would be unlikely to affect humans. Uses that would entail higher risk of human exposure would require filtration and other advanced treatment methods.

Does IWM involve human consumption of treated wastewater?

No. We have not reached the situation in the eastern U.S. to willingly take the risk of unknown, long-term health impacts that might occur through direct consumptive reuse of treated wastewater.

Does IWM involve human consumption of captured rainwater?

In certain situations, where a public water supply is not available, or where adequate water of acceptable quality cannot be drawn from a well on the site, consumption of treated rainwater is a plausible alternative. The water should be passed through a small-pore filter (similar to the type of filter used for household “point-of-use” treatment) and disinfected prior to consumption.